Shulk Gets Wrecked - Robin Again
by Bunnybunnyfairy
Summary: Shulk, being a scientifically-minded fellow, eagerly accepts the opportunity to help Robin when he is invited to participate in an "experiment." MA rating, 18 and older only, please.
1. Shulk Wrecks Himself

Robin paced along the side of his bed in his quarters, safely separated from the barracks he shared with his companion fighters. On the bed itself sat the object of his consideration, perched cheerfully with one knee pulled up beside him, resting his weight through his hands on the ankle of that leg.

 _ _Oh, Shulk,__ Robin thought, tilting his head as he admired the other boy, __Don't look so cute and innocent like that. It makes me feel worse for roping you in to my filthy games like this.__

Out loud, he only said, "Thanks for dropping by, Shulk. I was glad to see you accept my invitation on such short notice."

"Of course I had to come!" Shulk chuckled, beaming. "When you said you wanted my help with an experiment, it was the least I could do. You've seen tons of my own experiments in the lab."

"This one's a little different," Robin muttered, though he remembered fondly the numerous interesting machines Shulk had built and glowingly shared with him. To one like Robin, who had had no prior experience with machines of any sort, even the simplest gyroscopes that only whirred and spun were fascinating new marvels to him. He lacked the ability to understand how Shulk constructed such things with his own hands, and admired him for it.

The experiment he wished to attempt today was nowhere near so admirable.

Shulk seemed to catch on, perhaps detecting Robin's heat signature rising. "Is it... a __sexy__ experiment?" He leaned forward as he asked, brilliant blue eyes wide.

"Well, yes, it is," Robin confirmed, allowing a smile to tug the corner of his mouth.

Shulk brightened even more, his own smile overtaking his features. "What are we waiting around for? Every second is a second wasted! This is for science!"

Robin silently thanked every God he could think of (some of which he knew personally) for the insatiable sex drive of youth.

* * *

Within minutes, encouraged by Shulk's enthusiasm, they determined to set things in motion. "In this experiment," Robin explained, helping Shulk out of his clothes, "I won't be touching you after the initial setup, and to disallow you from touching yourself as well, you must be restrained. May I tie you?" Shulk, curious and eager, nodded. Robin had produced a length of soft silk, and Shulk allowed him to hold his arms behind his back so that one forearm rested on the other, and tied them together.

"This is a little... well, kinky," Shulk tested the restraint, smiling as he found it not too uncomfortable, heat already coloring his face.

"Yes, it is pretty kinky," Robin smiled, too. "I thought that if I'm to practice this sort of experiment on anyone, it ought to be you."

"I am honored that you thought of me," Shulk said with mock pride. "All right, kinky experiment is go."

"Please remember, however," Robin urged, shrugging out of his own robe and hanging it near the door. "If at any time you want to stop, the word is 'pause.'" Shulk giggled, doubting there was anything Robin could throw at him that would make him want to stop, but grateful for the thought of his safety all the same.

* * *

Shulk was situated on his knees on the soft quilt comforter of Robin's bed, naked and wrists bound. Robin had produced a pretty crystal jar, its edges beveled like a cut diamond's sides. The jar was filled with a creamy balm, which Robin scooped a small amount of with his fingers. "You'll like how this starts," he promised Shulk. "First, I get to massage you." He was rubbing his hands together to coat them with the balm, and leaned in toward Shulk, resting one knee on the bed for balance.

It was a slow, sensuous massage over his erogenous zones, something both of them simply enjoyed in the quiet for a while. Robin enjoyed the soft handfuls of Shulk's butt, enjoyed trailing his fingers down the crevasse, giving his hole a little swirl so that it was covered with balm as well. Shulk tensed and relaxed, closing his eyes as he let Robin's hands explore him.

Working from the front and with a new slathering of balm, Shulk's inner upper thighs were massaged next. "It's surprisingly warm," he observed, in part to distract himself as Robin gently handled his balls.

Next, Robin had the pleasure of feeling Shulk hardening in his hands as he rubbed the balm lovingly over his cock. It was not much unlike lubing him up, although the consistency of the cream was different.

"Now, how is this different from any other 'experiments' of ours?" Shulk asked playfully of Robin's apparent handjob, grunting through the sensation.

"Oh, just wait and see," Robin promised, and just to punish Shulk's impatience, he paid special attention to the folds around the head of his cock, even rubbing the balm over the very tip, cruelly applying pressure there with his thumb. He was satisfied with the louder grunt Shulk produced in response to the tender stimulation, watching with fascination the contraction of his stomach muscles. Inspired, he coated some of the balm there, too. As tempting as it was to continue here, Robin didn't want Shulk __too__ stimulated before the trial even began, so he retreated to move on to the next part.

"All right, one final step in the setup phase," Robin was close to his face now, a tiny bit more of the substance on the tips of his fingers, which he held near his mouth. "Open up."

"Is that stuff safe to ingest?" Shulk questioned, unsure.

Robin bit back his tongue to hold back the words, __That's what we're going to find out,__ and said instead, "I would never put you in any danger." His fingers went deep into Shulk's waiting mouth, coating the back of his tongue.

Shulk closed his eyes and lapped it up. He was surprised by the flowery flavor. He wished he had greater knowledge about plants and herbs, so that he might guess at the effects all this might have on him. He thought of perusing Robin's bookshelf for a plant life encyclopedia, distracted by the enticing thought of learning something new, but came back when Robin began to retract his fingers.

As Robin pulled his fingers out, Shulk playfully sucked and licked them. His eyes opened and he did not break eye contact with Robin, gazing at him lustily as he searched for every last drop of the substance with his tongue. Robin beamed, thoroughly aroused, thinking, __Oh, I could not have picked a better person for this.__

It was with some difficulty that he retreated from the bed, leaving Shulk on his knees there. "Tell me about everything that you feel," he instructed, twisting the lid back in place on its jar. "It should be kicking in soon."

"It's getting warmer already. I mean... where you rubbed it," Shulk blushed a little. Then he asked, "This isn't going to __burn__ or do anything painful, is it?" Truthfully, he was feeling a small amount of trepidation about having the unknown substance on his most sensitive areas.

"It shouldn't," Robin assured, "But if it does get too hot, please do not hesitate to say 'pause.'"

"Right," Shulk nodded, comforted.

* * *

Soon, Shulk began to feel a change in the effects of the balm, in addition to the heat. He turned his head, attempting to place what he was feeling and put it into words for Robin. "It feels... like some kind of movement, sort of," he attempted, hoping that didn't sound weird. It was a stimulating sensation, and his own breathing involuntarily grew heavier. He felt sensitive parts of himself twitch in response. He leaned over, folding over his crotch, wishing his arms were free so he could further stimulate those areas, but he could do nothing but resign himself to the effects of the balm. It washed over him in hot waves, seeming to simulate pressure and movement. Some of it radiated from his asshole, where Robin had coated a heavy layer, and traveled over his balls, all the way up and back down his cock. The very tip felt to be another radiating point, the origin of the waves that pulsed up and down his shaft, concentrating where he was most sensitive. He felt the waves extend over his thighs and stomach as well.

Shulk's hips bucked, an involuntary movement. His breath came heavily, his face and neck flushed deep red. Robin observed the strain on his member, thick and hardened with want, already dribbling from the tip. Another thrust, this one accompanied by a helpless mewling cry.

"R-Robin," Shulk managed, struggling to form words through the combination of labored breathing and mental fog.

"Yes?" Robin was ready to leap in the moment Shulk asked to "pause," but the request never came.

"I need... hah... would you... touch me? Anywhere... I need... hihh... I need __something...__ "

"Sorry," Robin apologized, hiding his amusement, "The experiment specifically calls for your reactions without any outside interference. But, tell me, what is it that you need?"

"I... need... something, __anything,__ in my..." Shulk couldn't seem to form the word, but he arched his back, perking up his backside, begging for stimulation beyond the sensations the balm supplied.

"Your what?" Robin smirked.

"My __ass,__ God, I need to be touched there, even if it's just your fingers, I – __ffffffuck,"__ he bucked again, giving a helpless, high little bark. Robin fully absorbed the luscious sight of the young man completely unraveling before him, using vulgar words he'd never uttered before.

"I have to... __fuck...__ please, would you... my cock, please, I've got to __fuck something,"__ his voice trailed off into a high whine as he bucked rapidly at nothing, his rigid cock twitching and pumping out more viscous liquid.

"Perhaps next time," Robin said, pretending to rest his hand on his chin in thought, but in fact masking the deep blush that crawled over his face. "This first run of the experiment must serve as the baseline for further tests." Shulk moaned long and loud at that, only half in disappointed response while the other half was simply the loss of control over his voice. His body was __wanting,__ but not __getting,__ and that denial fueled the __want__ all the more.

"Ah, I know something I can do," Robin realized, picking up the jar again.

"Wh-what?" Shulk heaved, eager for Robin's touch __anywhere__ on his overstimulated body. Leaning onto the bed again, Robin rubbed some balm between two fingers, then over Shulk's nipples, the contact on such an erogenous zone making him gasp and __whine__. But then Robin backed off again, leaving Shulk without the stimulation his body begged for. It activated quickly, and Shulk cried out as the heating sensation overtook his nipples, erect and sensitive to every wave the substance pulsed out over them.

"Ah, hah, hah," Shulk's voice was nothing more than high, airy breaths now, as his entire body bounced on the bed, high on his knees in response to an invisible assailant that accosted his ass, his thighs, his bouncing privates, his throbbing cock, and now his perked, sensitive nipples as well. Observing all of this, Robin's own breathing had grown a little heavy, too. He felt some __want__ of his own. He __wanted__ to move forward and get his hands all over Shulk's begging body, and take that hard, thrusting cock in his hands or mouth, and cover his gasping, open mouth with his own. But he held back in a fantastic display of self control.

Shulk's desperate movements grew even more frenzied as his eyes shut tight, tears forming at their corners. Under Robin's awe-stricken gaze, after many more moments of listening to Shulk's high, breathy moans, the back of his throat released one final squeak as his back arched and his eyelids fluttered. In that final thrust, cum spilled from his straining cock as veins bulged along its length, the liquid running in rivulets down the shaft while a few loose globules splat onto the bed. Shulk's back held him in that arch for several moments as his cock unloaded a few more spurts, then his shoulders slumped forward and his knees gave out, falling back to the bed in a weakly sitting position with a deep, relieved sigh.

Robin still absorbed everything he'd just observed, mentally replaying the scene with the hope of committing it to memory. He gave Shulk a few moments to catch his breath before moving to him, joining him in sitting on the bed. He tugged at one end of the silk that restrained Shulk's forearms to untie it, his arms simply falling limply to his sides. Robin tenderly brushed back the blond hair from Shulk's face, finding the roots soaked with sweat. Just as he began to caress the young man's tired face, Shulk surprisingly closed the remaining distance between them, devouring Robin's lips in a ravenous kiss.

With wet, open-mouthed motions, he was kissed over and over, Shulk's tongue lunging deep inside his mouth. Robin was perfectly content to take these deep kisses, thinking of it as the other young man taking out his frustration on him, so to speak, but suddenly he recognized a new, unfamiliarly sweet taste on Shulk's tongue. "Ah! Wait!" he pulled back immediately, explaining, "The balm! It can still... activate..."

"I thought it might," Shulk grinned, using his new vantage point to slip the silk around Robin's wrists while he had the opportunity of surprise. "Your turn."


	2. Robin Gets Wrecked

As far as Shulk and Robin's relationship went, if one was melting and moaning under the other's touch, it was always Shulk. He __never__ got to see Robin unraveled, but here he was, already panting, and with sweat beading along his hairline. He looked __especially__ vulnerable, wrists bound just as Shulk's had been only a few minutes ago, although the spontaneity of the situation called for them simply being held above his head rather than behind the back as Shulk's had been. And in that position, Shulk couldn't easily remove all of what remained of his clothes, so his tunic was pushed up to his arms, tucked behind his head to get it out of the way. The sight was __incredible.__

After sneakily "feeding" Robin the aphrodisiac cream, Shulk did his best to get those clothes undone and grabbed the jar, coating his fingers with it. As he massaged Robin much in the same manner that Robin had massaged him, he leaned his face close to Robin's ear.

"Just so you know," he said low, "The rules for that safe word still apply..."

Robin unleashed a single breath of a laugh, halfheartedly giving the restraints at his wrists a little struggle. "I suppose I deserve at least this, huh?"

He was trying to keep his cool, trying to maintain the illusion of being unflappable, but his sweat and escaping grunts gave him away. Shulk knew that Robin understood that he could ask to stop if he truly wanted to, but he seemed alright with going through with it. Shulk, having just experienced this himself, wasn't sure he wanted to make Robin suffer it, too, but... backing up, he looked over the vision that was Robin's vulnerable form, skin glossy where the balm hadn't entirely soaked in yet. It had activated instantly, already having been ingested in his mouth, which apparently unleashed its effects.

It would be a waste not to enjoy it.

Robin didn't bounce and thrust as Shulk did, but his cock was just as fully hard and strained, and his hips gave little half-bucks when he failed to hold back the involuntary movements. Shulk marveled over the sight of this struggling Robin, arms bound above his head, sweat sheening over his pale, shuddering body. He could see very visibly where the heated blush began at his neck, making his face look feverish, exacerbated by his labored breathing and knotted eyebrows. Robin had thinner limbs than Shulk, a slender waist with a stomach that dipped in at the navel, and no muscles pronounced in his chest. Shulk just __couldn't__ leave all of that untouched, especially not with the soundtrack of these rare gasps and small grunts playing in his ears as well.

Despite having threatened the opposite, Shulk lowered himself to Robin's crotch level, wetting his lips in anticipation as he laid his own still-naked body against the bed. From Robin's point of view, the way Shulk laid between his legs, knees pulled in underneath him, waist arched and ass in the air, doglike – the sight alone was just as stimulating as the pulsing, hot sensations ebbing and tiding over his most private areas. He could do nothing to hold back the cry that escaped the back of his throat as he felt wet precum escape his cock, beading at the tip.

Shulk watched the pearl form in front of him in a hot daze, taking it as an invitation to press his thumb against it, giving it a little swirl. Robin's hips jerked – still not quite a thrust. Shulk was determined to unravel him yet, and pressed a kiss into the tiny puddle instead, his fingers curling comfortably into place around the shaft.

Shulk had made attempts at oral sex with Robin prior to this, but by all accounts he was deemed to be __terrible__ at it. Well, with Robin overstimulated like this and suffering that desperate __want__ to be touched just as Shulk had, he was pretty sure that just about __anything__ he did down here would provide positive results. With what had to be the most satisfying sound Shulk had heard yet in his life, Robin __whined__ when Shulk put his lips over the head. It was the highest sound Shulk ever expected to hear from his partner, who was usually silent when he wasn't murmuring low, erotic whispers to him in their other sexual encounters. The sound __alone__ was enough to send blood rushing back through Shulk's cock, feeling __too__ tender after he'd just orgasmed so strongly in his own experience.

He lowered his head, taking the length further into his mouth, moving his tongue around the underside and feeling over the strained veins with it. He tried to work up saliva to provide a warm, wet experience for his partner, self-conscious about how embarrassingly he'd failed to please him in their previous attempts at this.

He moved his head up and down the length, keeping it wet (the balm helped a bit in slicking it, too), keeping his teeth covered, and keeping his tongue moving, exploring. On either side of him, Shulk was aware of the muscles in Robin's thighs tightening as he moved his legs, curling his toes. Worried about the quality of his work, Shulk slacked, looking up to gauge Robin's expression.

There were __tears__ running down either side of his face. They made wet trails over his cheeks, and he could watch them form droplets and fall from under his chin. His eyelashes were clumped and heavy, gasps and hiccups escaping his mouth, shoulders trembling as he sobbed. Shulk was at once alarmed, about to ask if he wanted to pause, when Robin took in a sharp breath and hoarsely ordered, "Don't __stop,__ for the love of every God watching over this Earth, keep __going!"__

At that moment, if Shulk really were a dog, that would have been where his ears perked up into points while his tail wagged with enough fervor to flap his backside away. With newly doubled- no, quadrupled-over enthusiasm, he devoured Robin's cock again, licking and sucking and bobbing his head with such ferocity that his nose touched Robin's stomach when he pulled in, white hair tickling his nose, and he could feel the folds around the head at his lips when he pulled back.

Robin __keened,__ and finally, __finally,__ his hips thrust, signaling that he'd thrown all resolve out the window, which nearly gagged poor Shulk, but he continued his work undaunted. Now that Robin was moving, too, Shulk needed to maintain rhythm, requiring a better grip. His hands wrapped around to grasp the soft skin of his buttocks. It made Robin cry out again, and Shulk remembered how oversensitive the balm made any areas it was rubbed over, so the simple action of his squeezing fingers provided greater stimulation than he realized.

Then, he got a little curious. What if he crept his fingers just a few inches inward? With Robin bucking all the while and Shulk taking his length in his mouth over and over, he worked his fingers further, until at last they rested on their prize. The high moan Robin released confirmed Shulk's suspicions that he was feeling that same desperate __want__ to be entered that Shulk had felt not terribly long ago, heightened by the balm, and so Shulk obliged by penetrating the hole with his index finger. Robin's thighs __squeezed__ Shulk on either side, but he continued his relentless assault on Robin's cock and asshole undaunted.

After that, Robin's thrusts were so frenzied and his gasps so high and breathy that it didn't come as too great of a surprise to Shulk that the cock in his mouth went fully rigid, spurting warmth down his throat. Now Shulk really did gag, pulling back to cough as the warm, thick stuff dripped down the back of his throat. Robin wasn't fully finished, however, and his next spurts spilled out to land near Shulk's lips, on his cheek, and sticking in some of the long strands of his bangs. One eye closed against the assault, Shulk hazarded a glance up, hoping to catch a glimpse of Robin's orgasming expression, but his head was tossed back, only giving Shulk a view of his arched body, stomach muscles pulled in tight. He lamented missing the sight of his partner's face, especially when Robin had gotten such a good view of his own just before this, but the memories of those rare sounds he'd gotten to hear from him made up for everything.

He remembered his finger was still embedded in the back, so he retracted it now, doing so as gently as he could, and Robin grunted in reaction as his slackening cock gave a final upward twitch. Since Shulk was down here anyway, he took the opportunity to lap up the dribbles of cum from the end of his softening cock, doing so gently with the knowledge that it was tender and sensitive after orgasm. Robin seemed grateful, sighing with great relief and running his hand through Shulk's sweat-dampened hair. The touch made Shulk realize that Robin had untied himself – and probably could have at any point, simply choosing not to. When Shulk finally pulled back fully, the act finished, Robin saw with surprise and delight that there was more than just sweat in his hair. He smiled tiredly as he wiped his cum from from Shulk's cheek with his thumb.

"How was that?" Shulk asked as he pushed himself back to a sitting position, a little dumbly, considering that all of the answers were written on his face. Both of their faces, really. Robin breathed a small chuckle in answer, his dark eyelashes still wet from crying – Shulk still couldn't believe Robin _ _cried__ – and the quills of his hair tussled and uneven from the combination of sweat and exertion. Shulk nuzzled into Robin's neck – now more like a kitten than a dog – enjoying his smell every time he inhaled, while Robin kept his fingers in Shulk's hair, caressing him.

"That was a successful experiment," Robin concluded, making Shulk laugh into his neck.

"A successful __kinky__ experiment," Shulk corrected. And after a moment of enjoying each other's presence in silence, he asked, "When's the next one?"


End file.
